Database memory management systems that handle large amounts of data typically store the bulk of user records in compressed page form. These compressed pages are stored in long term storage in a high capacity storage device, such as a hard disk. Whenever a change is made to a user record, the compressed memory page is fetched from the storage device and stored in operating memory. Once the compressed memory page is in operating memory, the page is uncompressed so that the affected user record can be changed.
Some databases store large amounts of user records that are rarely edited but are often deleted. One example of user records that are rarely edited are addresses included in a mailing list. Addresses are often removed from these lists but the address information is rarely updated. Hence, the processing resources necessary to uncompress and re-compress a data page are often employed simply to delete a record or to perform other operations that do not require access to the contents of the compressed user records themselves.